Harvesters, such as self-propelled windrowers, are used in the agricultural industry to harvest and/or a variety of crops. Headers having different components are interchanged on the windrower based on the desired operation and the type of crop being harvested and/or cut. Headers used for cutting crops generally include ground feeler arms or gauges that extend from the bottom of the header and control the overall height of the header relative to the ground, thereby regulating the stubble or cut height of the crop.
For example, FIG. 1 shows a side view of a traditional header 10. The header 10 includes an attachment mechanism 18 that can be used to detachably couple the header 10 to a harvester 20. Harvested crop can be introduced from the header 10 into the harvester 20 and, particularly into a processing system 30 of the harvester 20. The header 10 includes a housing 12 with a cutter bar 14 disposed at or near a bottom surface of the housing 12. Cut height cylinders (not shown) are generally mounted on the harvester base unit and act upon the lift arms. The header 10 includes multiple ground feeler arms or gauges 22 pivotally mounted to an axle 24 aft of the cutter bar 14. The angle at which the ground feeler arm 22 extend from the axle 24 control the position of the cutter bar 14 relative to the ground, thereby varying the desired stubble or cut height of the crop.
In particular, feedback information for the desired cut height is sent to a controller via multiple ground feeler arms 22. The arms 22 are pivoted from the axle 24, rotating down and up by an angle 26 from a position where the cutter bar 14 is contacting the ground to an elevated position where the cutter bar 24 is a predetermined distance above the ground. Raising the cutter bar 14 to a maximum height 28 (e.g., 18 inches) above the ground generally requires the arm 22 to rotate through a large arc, resulting in the arm 22 being nearly vertical when the cut height is set to the highest elevation or the header 10 is fully lifted at the end of a row. The vertical orientation of the arm 22 causes the arm 22 to dig into the ground when the header 10 is lowered from a full lift height (e.g., an elevation much higher than the cut height), preventing the header 10 from returning to the ground since the arms 22 dig into the ground and hold the header 10 up rather than sliding back under the header 10 as it is lowered.
The arm 22 shown in FIG. 1 can be replaced with a longer arm 22 for higher cut heights, since the longer arm 22 would not have as vertical of an angle 26 when lifted, allowing the arm 22 to slide back under the header 10 when the header 10 is lowered. However, longer arms 22 lose resolution as they rotate through less of an arc (fewer degrees of rotation) than a shorter arm 22 being lowered the same vertical distance. Such resolution is critical for low-level cutting close to the ground. Thus, manual interchanging of the arms 22 is generally necessary based on the desired cut height, resulting in a loss of harvesting time.